Skin Flashcards
Dermatology
Lumps and bumps Psoriasis and eczema Oral manifestations Important infections (!) Skin tumours
Erysipelas
Acute infection typically with a skin rash, usually on any of the legs and toes, face, arms, and fingers
Infection of upper dermis and superficial lymphatics
Usually caused by beta-hemolytic group A Streptococcus bacteria on scratches or otherwise infected areas
Examinations
Examination and description of lumps
Neck examination
Common skin lumps
Skin cancers
Most common skin conditions
Psoriasis, exzema, contact dermatitis
- differential may be difficult
- red patches, swelling, itchy, painful
Psoriasis vs eczema
Psoriasis -well defined -red with scaly surface -adults -unknown cause -trunk, limbs, knees -scalp and nails -psoriatic arthritis Eczema -poorly defined -red without scales -children -allergens, -face, hands -NOT scalp and nails -no arthritis
Koebner phenomenon
Wheels appear after scraping skin
-appearance of skin lesions on lines of trauma
Contact dermatitis
Type of inflammation of the skin resulting from irritants or allergens
-only superficial layers of skin affected
Psoriatic arthritis
typically causes affected joints to become inflamed (swollen), stiff and painful
-long term condition that can get progressively worse
Aetiology of psoriasis
HLA association
T-cell mediated
Keratinocyte proliferation early
Aetiology of eczema
No HLA association Uncertain cause IgE -skin barrier permeable -atopic eczema: Type 1 -allergic contact dermatitis: Type 4 Hyperkeratosis late
Treatment of psoriasis
Reduce keratinocyte proliferation -vit D -coal Tar -dithranol -retinoids Immune suppression -steroids -methotrexate -biologicals: TNF blocker
HLA/ MHC
HLAB27
On surface of our cells to tell us that these are our own cells
-cell-surface proteins responsible for regulation of the immune system in humans
The presence of HLA-B27 is associated with certain autoimmune and immune-mediated diseases, including ankylosing spondylitis, reactive arthritis, and sometimes lesions on your skin
If it’s wet dry it, if it’s dry wet it, if in doubt stick some steroids on
Wet, oozing lesions should be dried, dry lesions should be hydrated and lubricated
Treatment of eczema
Identify triggers Emollient cream Topical steroids Antihistamine for itch Antibiotics if infected
Oral manifestations of skin disease
Lichen planus
Herpes infections
Blistering conditions
Lichen planus
Itchy, papular rash Flexor surfaces, mouth and genitalia Haven't found antibody to it yet -develop destruction of own tissues (not severe) -chronic inflammatory infiltrate
Lichen planus typical histological appearance
Band-like T cell infiltrate
Saw-shaped rete ridges
Acanthosis (thickening) of basement membrane
Herpes infections
Chickenpox
Herpes zoster (shingles)
Herpes simplex virus
Recurrent herpes labialis
Associations of herpes
Whitlow
Ocular keratitis
Whitlow
Herpetic whitlow is a lesion (whitlow) on a finger or thumb caused by the herpes simplex virus
Painful infection that typically affects the fingers or thumbs
Post herpetic neuralgia
Nerve pain which occurs due to damage to a peripheral nerve caused by the reactivation of the varicella zoster virus
Examination of lumps
Site Size Shape Mobile or fixed Consistency Surface Covering skin/ mucosa Pulsatile etc.
Site of lumps
Neck
Face, scalp, nose
Size, shape
Two dimensions unless it is round
If round: fruit (pea/ grape), then golf ball size
